Tire bead sealing and supporting means for retreading mold

ABSTRACT

An apparatus is provided for retreading tires without the use of an air bag or tube. Sound fluid tight integrity during initial tire inflation is provided by a bead seater means, preferably in the form of an internal annular belt which presses the tire beads against outer rims to produce a sealing engagement. Inflation air passes through a valve in one of the rims and through the bead seater means into the tire.

United States Patent Shellabarger [4 1 Sept. 12, 1972 [541 TIRE BEADSEALING AND 2,866,228 12/1958 French ..l8/ 18 F SUPPORTING MEANS FOR2,871,514 2/1959 White ..18/1 BF RETRE m MOLD 2,903,741 9/1959 White..18/45 T X 3,135,996 6/1964 Sinyser........,..............l8/18 F [721lnvenm "Wald P m 1110 3,195,179 7/1965 Laube ..18 TP Mac Nichol Lane.Chattanooga. 3,238,982 3/1966 Darr .........151/13 x Tenn. 37421 22 i Au1 19 9 Primary Examiner-J. Howard Flint, Jr.

Attorney-Wynne and Finken [21] App1.No.: 846,824

[57] ABSTRACT [52] US. Cl. ..42S/2l, 425/24, 425/38, An apparatus isprovided for retreading tires without 425/90 the use of an air bag ortube. Sound fluid tight integri- 51 1111. 5/04 y during initial lireinflation is Provided y a head 53 Field 61 Search ..l8/l8 F, 45 T sealermeans, preferably in the form of an internal nular belt which pressesthe tire beads against outer 6 R f rims to produce a sealing engagement.Inflation air [5 l e Cited passes through a valve in one of the rims andthrough UNITED STATES PATENTS the bead seater means into the tire.2,077,506 4/ 1937 Woock ..18/ 18 F 2 Claims, 5 Drawing Figures PatentedSept. 12, 1912 3,690,794

2 Sheets-Sheet 1 -l W i FIG] Fl 2 INVENTOR DONALD ELSTON SHELLABARGERATTORNEYS TIRE BEAD SEALING AND SUPPORTING MEANS FOR RETREADING MOLDThis invention relates to the retreading of tires and particularly to ameans for sealing the beads of a tire in a conventional retreading moldin a manner which enables inflation of the tire without a tube.

An example of equipment requiring a tube is shown in the 1958 U.S. Pat.No. 2,866,228 to E. E. French. This invention provides replacement beadengaging rims and a bead seater means for equipment of this type; theinflation tube is eliminated.

Increased efficiency in operation is available with this invention sincethe tube need not be inserted and the problem of the tube sticking tothe tire is eliminated. The expense of replacing worn tubes iseliminated.

It is recognized that tubeless retreading equipment is not new. However,the problem of providing a fluid or air-tight seal has presentedoperational difficulties which apparently have prevented acceptance bythe industry.

This invention provides a kit for conversion of the type equipment shownin U.S. Pat. No. 2,866,228; the cost of such conversion is low; the sealproduced is sound; and operational and maintenance costs are reducedsignificantly.

The two telescoping rims which engage the tire beads have an O-ring sealat the telescopic joint. Each tire bead is forced against a rim flangeby the bead seater means to produce an initial fluid tight seal. Thebead seater means is preferably of a flexible material such as rubber,plastic, leather, etc. to facilitate insertion between the beads and hasan inside diameter larger than the telescoping rim tube portions todefine therewith an annular fluid conduit for annularly conducting airfrom a valve stem on a rim to openings in the bead seater means toenable tire inflation. This eliminates the necessity for aligning asingle opening, when employed, in the ring with the valve stem andspeeds up the operation.

Bead breakers are provided in the form of air tubes in each rim.

Alternatively, the rims may be coated with Teflon or some similar lowfriction material to facilitate tire removal.

Further objects and advantages of the invention will be apparent fromthe following description taken in conjunction with the accompanyingdrawing wherein:

FIG. 1 is an exploded view of the two rims and a bead seater meansshowing two forms for initial inflation air entry into the tire, onebeing an enlarged opening and the other being a foraminous belt withsmall passages throughout its entire length;

FIG. 2 is an outer end view on reduced scale of the larger rim;

FIG. 3 is a cross sectional view of the three parts mounted in astandard retreading equipment with the tire beads positioned for firmseating on the annular bead flanges when the rims are moved intoengagement therewith;

FIG. 4 shows the rims in final seating position with the telescopicjoint sealed and the tire beads forced by the bead seater means intosealed engagement with the rims awaiting initial inflation; and

FIG. 5 shows the tire in its final inflated and aligned position.

The replacement rims 22 and 23 and the bead seater means 27 whichreplaces the tube are shown in FIGS. 1 and 2. As seen in FIGS. 3 to S, atypical retreading unit of the type mentioned includes annular pressureplates 28, 28, and fixedly attached side wall members 31, 31, which aremoved toward and away from matrix 16.

Matrix 16 is suitably mounted in arcuate sections on a frame forswinging into position around the tire l8. Suitable moving means such asshown in U.S. Pat. No. 2,866,228 are incorporated herein by reference asindicated in part by arrows 100.

The beads 46, 46 of the tire 18 are engaged at their outer radial sidefaces 19, 19 by annular bead flanges 20, 21 of rims 22, 23 respectively.The inner radial side faces 24, 24 of the beads are engaged by theradial faces 25, 26 of the bead seater ring 27. The annular end faces35, of the beads seat on the annular seats 36, 37 of the rims.

The bead seater ring 27 may be constructed of leather belt material sothat it has some resilience and can be flexed for insertion intoposition between the beads of the tire.

Each cylindrical rim 22, 23 has an outer series of radial mounting cars40 which mate with similar mounting ears 36 of the side wall members 31.

Suitable means, when desired, are provided in the standard equipmentmentioned for axially sliding the rims 22 and 23 with respect to theside wall members 31, the ears 40 of each rim being biased by adjustablesprings into engagement with cars 36. When the tire is inflated, therims move outwardly against the predetermined bias (arrows 200) untiltheir bead flanges 20, 21 engage their respective ears 36 at which time,the two beads 46 will be in accuate firm contact with the concentricrims and in the desired predetermined position for retreading.

FIG. 3 shows the parts assembled and ready for the final inward tireembracing movement of the side wall members 31 and the rims 22, 23.

FIG. 4 shows the side wall members 31 in contact with the matrix 16, therims 22 and 23 in their inwardly biased position, and the tire beads 46firmly forced by the ring 27 into fluid sealed engagement with the beadflanges 20 and 21. The fluid tight telescopic joint 51 is in anestablished condition.

Inflation then takes place.

Certain equipment designs would involve no outward movement of its rimsbefore retreading. However, alignment advantages appear to reside indesigning the rims 22 and 23 in a manner which allows a predeterminedoutward axial movement of the tire beads and sidewalls.

Various systems can provide for this. In the schematic system shown inFIGS. 4 and 5 coil springs 50 bias the rims inwardly. When sufficientair pressure is developed the tire beads 22 and 23 force the rimsaxially outwardly to the seated positions shown in FIG. 5.

It will be noted that ring 27 is free of the tire in FIG. 5 therebyavoiding any adhesion problems and opening larger air flow paths toexpedite inflation and deflation.

In practice it has been found that a leather belt about one-quarter inchthick loosely surrounding the rims is most effective, its diameter beingabout one-eighth of an inch larger than the rim portions it surrounds.The belt may carry many minute holes or some small holes or just onelarge hole. Separate spacers (not shown) positioned around the beadsinside the tire have served the purpose which is to seat the tire beadsto enable initial inflation for the establishment of a firm fluid tightseal against the rim bead flanges.

As mentioned, this invention is desigied to provide a replacement kitfor presently existing equipment. US. Pat. No. 2,866,228 is one type ofequipment and its design has been changed to include camming of thelocking ears for adjustment. The instant invention can be designed tooperate on many types of equipment, those which utilize the inwardlybiased rims and those which do not. The key features are the sealing ofthe rims and the initial sealing of the tire beads to the rimsaccomplished by spaced discrete elements, an open ring framework, aforaminous belt, the type belt with many small holes 80 shown in FIG. 1,a belt with a single hole 81 as shown in FIG. 1 and the like.

FIGS. 1 and 2 show the kit and it will be noted that valve 83 providesthe means for introducing air directly into the tire through bead seatermeans 27. Air tubes 84 and 85 provide bead release means for separatingthe tire from the rims after retreading. It will be noted that the rimsof US. Pat. No. 2,866,228 may be utilized by merely making the rim tubesairtight at the telescopic joint and adding the required inflation valveand bead seater means. The O-ring seal is preferred but other seals maybe employed.

l claim:

1. Means for concentrically sealing and supporting the beads of a tirewithin a circular retreading mold 4 comprising:

a pair of cylindrical rims having an annular bead flange extendingradially outwardly and an annular tube portion extending laterallyinwardly from its flange, the tube portions being in a telescopedrelationship, one of said tube portions being longer than the other andone of said tube portions having an O-ring groove at its end;

an O-ring positioned in said groove to provide a fluid tight seal in thetelescopic joint;

a bead seater ring of flexible material encircling said tube portions,said ring having radial faces for engagement with opposed inner portionsof the beads of a tire, each radial face and its respective adjacentannular bead flange being adapted to sandwich their respective tire beadtherebetween to provide a fluid seal,

said bead seater ring having an opening for allowing fluid flow toenable inflation and deflation of the tire, said ring having an insidediameter greater than the outside diameter of the telescoped tubeportions to provide an annular fluid conduit,

a tire inflation valve means positioned in a tube portion between theO-ring seal and its bead flange, each rim having a fluid bead releasemeans.

2. Means as defined in claim 1 and wherein the bead engaging faces ofsaid rims have a coating of a material which inhibits adhesion of thebeads thereto.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,690,794 Dated September 12, 1972 Invent (:6) SHELLABARGER It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 4, line 2, after "rims" insert each rim-- Signed and sealed this23rd day of January 1973..

(SEAL) Attest:

EDWARD M.PLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents PO-IOSO (10-69] USCOMM-DC 60376-P59 9 U.S. GOVERNMENYPRINTING OFFICE: ID! O36G-334.

1. Means for concentrically sealing and supporting the beads of a tirewithin a circular retreading mold comprising: a pair of cylindrical rimshaving an annular bead flange extending radially outwardly and anannular tube portion extending laterally inwardly from its flange, thetube portions being in a telescoped relationship, one of said tubeportions being longer than the other and one of said tube portionshaving an O-ring groove at its end; an O-ring positioned in said grooveto provide a fluid tight seal in the telescopic joint; a bead seaterring of flexible material encircling said tube portions, said ringhaving radial faces for engagement with opposed inner portions of thebeads of a tire, each radial face and its respective adjacent annularbead flange being adapted to sandwich their respective tire beadtherebetween to provide a fluid seal, said bead seater ring having anopening for allowing fluid flow to enable inflation and deflation of thetire, said ring having an inside diameter greater than the outsidediameter of the telescoped tube portions to provide an annular fluidconduit, a tire inflation valve means positioned in a tube portionbetween the O-ring seal and its bead flange, each rim having a fluidbead release means.
 2. Means as defined in claim 1 and wherein the beadengaging faces of said rims have a coating of a material which inhibitsadhesion of the beads thereto.